This invention relates to improved methods and apparatus for collecting information, more particularly, electronically collecting data from multiple locations such as, for example, data collection from an array of sensors.
The successful and cost effective manufacture of many common components (e.g. integrated electronic circuits) requires that processing conditions or properties be maintained at optimal values over relatively large areas or volumes. The ability to obtain process condition data from many, discrete locations within a processing system (i.e. spatially resolved data) is very valuable in establishing and maintaining optimal component yields and performance. Further, many common processing operations require that process variables change in a consistent, reproducible way as a function of time (i.e. process trajectory) rather than have a single, time independent value. The ability to obtain process condition data at many, discrete points in time (i.e. temporally resolved data) is also very valuable in establishing and maintaining optimal component yields and performance.
Most sensors and sensing methods either obtain data at discrete physical locations (e.g. thermocouples measuring temperature) or measure an average (or integrated) value for the entire process area or volume (e.g. optical emission from a plasma discharge). These limitations are usually an inherent property of the sensor and/or measurement parameter. There are a number of standard methods and approaches that have been developed in an attempt to obtain spatially and temporally resolved process data, each of which has its own set of strengths and weaknesses. Descriptions of some methods that have been used can be found in United States patents U.S. Pat. Nos. 5,907,820, 5,959,309, 5,967,661, and 6,244,121.
Clearly, there are numerous applications requiring high accuracy methods and apparatus for spatially resolved and time resolved data collection from one or more sensors. Still further, there is a need for methods and apparatus that enable limited data acquisition and measurement resources to be more efficiently shared by a large number of sensors.
This invention pertains to improve data acquisition such as for mapping one or more parameters spatially, temporally, or spatially and temporally. Practicing aspects of the present invention includes data collection steps of activating multiple crosspoint nodes by applying electrical signals to the crosspoint nodes simultaneously and making measurements for one or more activation states. Parasitic correction measurements are also performed. The parasitic correction measurements are applied to the data from the data collection steps so as to obtain corrected data. Data representing the condition of one or more nodes are then mathematically extracted from the set of corrected data.
One aspect of the present invention includes apparatus for acquiring data. In one embodiment, the apparatus includes output electrical conductors, input electrical conductors, and sensors. The sensors are capable of presenting a measured parameter as an electrical impedance. Each of the sensors is connected with one of the output electrical conductors and one of the input electrical conductors so as to form an array of crosspoint connections. Applying electrical signals to the output electrical conductors and measuring electrical signals at the input electrical conductors, generates sufficient information to correct for parasitic current sources and derive the measured parameter of each sensor using algorithms that include equations for combining electrical impedances. The apparatus also includes a controller for applying the electrical signals, for measuring the electrical signals, and for deriving the parasitic source correction for the measured parameter.
Another aspect of the present invention includes methods of acquiring data. In one embodiment, the method is used for obtaining data from an array of sensors in a crosspoint network. The sensors are capable of representing one or more measured parameters as electrical impedance. The method includes the step of applying a pattern of electrical signals to the sensors. The method also includes measuring electrical signals from the sensors. Still further, the method includes the step of deriving measurement data corrected for parasitic sources for each of the sensors; the step includes using the corrected measured electrical signals and algorithms that include equations for combining electrical impedances.
Another aspect of the present invention includes a computer-implemented algorithm for deconvolving combined electrical impedances from an array of sensors. The algorithm is derived from equations that represent combined discrete impedances. The equations are manipulated to obtain a set of equations having the number of unknowns equal to or less than the number of equations. The algorithm further includes the mathematical steps for applying parasitic current source corrections and for solving the equations using measured electrical data representing the combined impedances and measurement data representing the parasitic current source.
It is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. In addition, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.
As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out aspects of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.
The above and still further features and advantages of the present invention will become apparent upon consideration of the following detailed descriptions of specific embodiments thereof, especially when taken in conjunction with the accompanying drawings.